package com.guoxin.facade;

/**
 * @author guoxin
 * @date 2019年8月26日
 */
public class Screen {
	private Screen() {
	}

	private static class ScreenHandler {
		private static Screen screen = new Screen();
	}

	public static Screen getInstance() {
		return ScreenHandler.screen;
	}

	public void up() {
		System.out.println(" Screen up ");
	}

	public void down() {
		System.out.println(" Screen down ");
	}
}
